Automobile users have been bothered by troublesome contamination of engines, especially the carbon deposits produced in the engines during the work process. It has been found that the fuel induction system, inlet valves, and combustion chambers of internal combustion engines are subject to carbon deposits which are formed under high temperature and derived from many sources, including materials in the fuel, products of fuel decomposition, products of fuel combustion, contaminants in the air which are not removed by filtration, and lubricating oil residues. The carbon deposits cause uneven distribution of the fuel charge in the cylinder of the engine, insufficient quantities of fuel supply in the various cylinders, and other problems which lead to poor engine performance, increased emissions, and poor fuel economy.
U.S. Pat. No. 3,876,704 discloses that N-long chain alkyl, N-hydroxyalkyl alkylenepolyamines are useful as detergents in hydrocarbon fuels.
U.S. Pat. No. 4,055,402 discloses that polyisobutenyl aminoethylethanolamine is useful as a gasoline detergent at levels from 50 to 200 parts per million.
CN1153813A discloses a cleaner consists of ethanolamine, butyl alcohol, ethyl ether, ammonia water, oleic acid, emulsifier, engine oil and kerosine, and it is used for cleaning stain and carbon deposit in internal combustion engines.
U.S. Pat. No. 5,407,453A1 discloses a composition comprising an alkoxy alcohol, an aliphatic alcohol, a liquid petroleum distillate, a liquid fatty acid, a volatile nitrogen base, polyisobuteny aminoethylethanolamine, and water may be used as an engine deposit cleaner which removers air and fuel induction system deposits, valve deposits, and combustion chamber deposits.
However, the use of aromatic hydrocarbon solvent, or glycol ether, or alkali may have environment concerns. Moreover, the cleaning efficiency of a typical detergent composition is not satisfactory to clean the engines which are contaminated by carbon deposits.
Accordingly, it is an object of this invention to provide cleaning compositions which can remove carbon deposits not only from fuel induction system but also from the inlet valves and combustion chambers of engines without above mentioned disadvantages. Instead of being used in the fuel itself, the cleaning compositions of the present invention are intended to be used as a single cleaning treatment of the engines.